TailraceTailrace
Integrations

MCP

Wrap MCP client transports with Tailrace - JSON-RPC error on block, rewrite on tokenize.

Enforce data policy on MCP tools/call and resources/read without tearing down the transport.

Quickstart

import { createTailrace } from "@tailrace/core";
import { withMcp } from "@tailrace/mcp";

const tailrace = withMcp(createTailrace());
const transport = tailrace.transport(sseTransport, { server: "salesforce" });

Peer: @modelcontextprotocol/sdk >=1.

Boundaries covered

LocationTailrace boundaryDirection
tools/call arguments{ kind: "mcp", server, tool, direction: "out" }Outbound
tools/call resultsame with direction: "in"Inbound
resources/read result{ kind: "mcp", server, tool: "read", direction: "in" }Inbound

Block → JSON-RPC error code: -32001 with { type: "policy_violation", entity, rule } (never the raw value).

Guides

Reference

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